Periosteal Osteoid Osteoma of femoral head in a spitz dog

The skeletal system is a common site for neoplasia in dogs and cats. primary bone tumors in dogs usually are more malignant than benign tumors. Osteoid osteoma is well described in humans, but there are known to be only a few cases in domestic animal species3. An uncommon benign bone tumor in dogs is Osteoma that composed of abnormally dense bone. This tumor commonly occurs in long bones like the femur and humerus; also, the mandible and skull in dogs.  Osteoma A 4-year-old neutered female spitz dog with a history of 2 days lameness in the left pelvic limb and no history of trauma, ataxia, incoordination of the hind limb in gate and knuckling was examined. In the Radiograph examination, periosteal reaction and osteolysis of the right femoral head in the pelvis region were present. Histological analysis with hematoxylin and eosin stain revealed irregular trabecular bone with varying mineralization bordered by a monolayer of osteoblasts and osteoclasts. The fibrovascular stroma of the tumor was adjacent by thick sclerotic bone, No Mitotic figures were present in mass. Based on imaging findings and histopathologic results, Periosteal Osteoid Osteoma was confirmed.